=head1 DESCRIPTION
-This is an unsupported alpha release, meant for intrepid Perl
-developers only. The included sources may not even build correctly on
-some platforms. Subscribing to perl5-porters is the best way to
-monitor and contribute to the progress of development releases (see
-http://www.hut.fi/~jhi/perl5-porters.html for info).
-
This document describes differences between the 5.005 release and this one.
=head1 Incompatible Changes
similar within interpolated strings to mean C<$$ . "1">,
but still allowed it.
-In Perl 5.6 and later, C<"$$1"> always means C<"${$1}">.
+In Perl 5.6.0 and later, C<"$$1"> always means C<"${$1}">.
=item delete(), values() and C<\(%h)> operate on aliases to values, not copies
=head2 On 64-bit platforms the semantics of bit operators have changed
If your platform is either natively 64-bit or your Perl has been
-configured to used 64-bit integers (say C<perl -V> and see what is
-your ivsize: if it is 8, you are 64-bit) , be warned that the
-semantics of all the bitwise numeric operators (& | ^ ~ << >>) have
-been changed. They used to be forced to be 32 bits wide, but now in
-the aforementioned platforms they are 64 bits wide. Most dramatically
-this affects the unary ~: what used to be 32 bits wide, is now 64 bits
-wide. If you depend on your integers being 32 bits wide, mask off the
-excess bits with C<& 0xffffffff>.
+configured to used 64-bit integers, i.e., $Config{ivsize} is 8,
+be warned that the semantics of all the bitwise numeric operators
+(& | ^ ~ << >>) have been changed. These operators used to strictly
+operate on the lower 32 bits of integers, but now operate over the
+entire width of native integers. In particular, note that unary C<~>
+will produce different results on platforms that have different
+$Config{ivsize}. For portability, be sure to mask off the excess bits
+in the result of unary C<~>, e.g., C<~$x & 0xffffffff>.
+
+=head2 The passwd and shell returned by the getpwxxx() are now tainted
+
+Because the user can affect her own encrypted password and login shell
+the password and shell returned by the getpwent(), getpwnam(), and
+getpwuid() functions are tainted.
+
+=head2 The shmread() now taints its variable
+
+Because other (untrusted) processes can modify shared memory segments
+for their own nefarious purposes, the variable modified by shmread()
+becomes tainted.
=back
=item C<PERL_POLLUTE>
Release 5.005 grandfathered old global symbol names by providing preprocessor
-macros for extension source compatibility. As of release 5.6, these
+macros for extension source compatibility. As of release 5.6.0, these
preprocessor definitions are not available by default. You need to explicitly
compile perl with C<-DPERL_POLLUTE> to get these definitions. For
extensions still using the old symbols, this option can be
=item C<PERL_IMPLICIT_CONTEXT>
-PERL_IMPLICIT_CONTEXT is automatically enabled whenever Perl is built
-with one of -Dusethreads, -Dusemultiplicity, or both. It is not
-intended to be enabled by users at this time.
+ NOTE: PERL_IMPLICIT_CONTEXT is automatically enabled whenever Perl is built
+ with one of -Dusethreads, -Dusemultiplicity, or both. It is not
+ intended to be enabled by users at this time.
This new build option provides a set of macros for all API functions
such that an implicit interpreter/thread context argument is passed to
(but subject to the other options described here).
See L<perlguts/"The Perl API"> for detailed information on the
-ramifications of building Perl using this option.
+ramifications of building Perl with this option.
=item C<PERL_POLLUTE_MALLOC>
-Enabling Perl's malloc in release 5.005 and earlier caused
-the namespace of system versions of the malloc family of functions to
-be usurped by the Perl versions, since by default they used the
-same names.
-
-Besides causing problems on platforms that do not allow these functions to
-be cleanly replaced, this also meant that the system versions could not
-be called in programs that used Perl's malloc. Previous versions of Perl
-have allowed this behaviour to be suppressed with the HIDEMYMALLOC and
-EMBEDMYMALLOC preprocessor definitions.
+Enabling Perl's malloc in release 5.005 and earlier caused the namespace of
+the system's malloc family of functions to be usurped by the Perl versions,
+since by default they used the same names. Besides causing problems on
+platforms that do not allow these functions to be cleanly replaced, this
+also meant that the system versions could not be called in programs that
+used Perl's malloc. Previous versions of Perl have allowed this behaviour
+to be suppressed with the HIDEMYMALLOC and EMBEDMYMALLOC preprocessor
+definitions.
-As of release 5.6, Perl's malloc family of functions have default names
+As of release 5.6.0, Perl's malloc family of functions have default names
distinct from the system versions. You need to explicitly compile perl with
C<-DPERL_POLLUTE_MALLOC> to get the older behaviour. HIDEMYMALLOC
and EMBEDMYMALLOC have no effect, since the behaviour they enabled is now
included (as required before), so there is no source incompatibility
from the change.
-=item Support for C++ exceptions
-
-change#3386, also needs perlguts documentation
-[TODO - Chip Salzenberg <chip@perlsupport.com>]
-
=back
=head2 Binary Incompatibilities
=head2 -Dusethreads means something different
-WARNING: Support for threads continues to be an experimental feature.
-Interfaces and implementation are subject to sudden and drastic changes.
+ WARNING: Support for threads continues to be an experimental feature.
+ Interfaces and implementation are subject to sudden and drastic changes.
The -Dusethreads flag now enables the experimental interpreter-based thread
support by default. To get the flavor of experimental threads that was in
5.005 instead, you need to run Configure with "-Dusethreads -Duse5005threads".
-As of v5.5.640, interpreter-threads support is still lacking a way to
+As of v5.6.0, interpreter-threads support is still lacking a way to
create new threads from Perl (i.e., C<use Thread;> will not work with
interpreter threads). C<use Thread;> continues to be available when you
-ask for use5005threads, bugs and all.
+specify the -Duse5005threads option to Configure, bugs and all.
=head2 New Configure flags
necessary APIs and datatypes, you should be able just to go ahead and
use them, for threads by Configure -Dusethreads, and for 64 bits
either explicitly by Configure -Duse64bitint or implicitly if your
-system has 64 bit wide datatypes. See also L<"64-bit support">.
+system has 64-bit wide datatypes. See also L<"64-bit support">.
=head2 Long Doubles
=head2 -Dusemorebits
-You can enable both -Duse64bitint and -Dlongdouble by -Dusemorebits.
+You can enable both -Duse64bitint and -Duselongdouble with -Dusemorebits.
See also L<"64-bit support">.
=head2 -Duselargefiles
-Some platforms support large files, files larger than two gigabytes.
+Some platforms support system APIs that are capable of handling large files
+(typically, files larger than two gigabytes). Perl will try to use these
+APIs if you ask for -Duselargefiles.
+
See L<"Large file support"> for more information.
=head2 installusrbinperl
=head2 SOCKS support
You can use "Configure -Dusesocks" which causes Perl to probe
-for the SOCKS (v5, not v4) proxy protocol library,
-http://www.socks.nec.com/
+for the SOCKS proxy protocol library (v5, not v4). For more information
+on SOCKS, see:
+
+ http://www.socks.nec.com/
=head2 C<-A> flag
You can "post-edit" the Configure variables using the Configure C<-A>
-flag. The editing happens immediately after the platform specific
+switch. The editing happens immediately after the platform specific
hints files have been processed but before the actual configuration
process starts. Run C<Configure -h> to find out the full C<-A> syntax.
=head2 Unicode and UTF-8 support
-Perl can optionally use UTF-8 as its internal representation for character
+ WARNING: This is an experimental feature. Implementation details are
+ subject to change.
+
+Perl now uses UTF-8 as its internal representation for character
strings. The C<utf8> and C<bytes> pragmas are used to control this support
in the current lexical scope. See L<perlunicode>, L<utf8> and L<bytes> for
more information.
=head2 Interpreter cloning, threads, and concurrency
-WARNING: This is an experimental feature in a pre-alpha state. Use
-at your own risk.
+ WARNING: This is an experimental feature. Implementation details are
+ subject to change.
Perl 5.005_63 introduces the beginnings of support for running multiple
interpreters concurrently in different threads. In conjunction with
functionally identical to one that was built with -Dmultiplicity, but
the perl_clone() API call will only be available in the former.
--Dusethreads enables, the cpp macros USE_ITHREADS by default, which enables
-Perl source code changes that provide a clear separation between the op tree
-and the data it operates with. The former is considered immutable, and can
-therefore be shared between an interpreter and all of its clones, while the
-latter is considered local to each interpreter, and is therefore copied for
-each clone.
+-Dusethreads enables the cpp macro USE_ITHREADS by default, which in turn
+enables Perl source code changes that provide a clear separation between
+the op tree and the data it operates with. The former is immutable, and
+can therefore be shared between an interpreter and all of its clones,
+while the latter is considered local to each interpreter, and is therefore
+copied for each clone.
Note that building Perl with the -Dusemultiplicity Configure option
is adequate if you wish to run multiple B<independent> interpreters
additional functionality of the perl_clone() API call and other
support for running B<cloned> interpreters concurrently.
-[XXX TODO - the Compiler backends may be broken when USE_ITHREADS is
-enabled.]
-
=head2 Lexically scoped warning categories
You can now control the granularity of warnings emitted by perl at a finer
=head2 Lvalue subroutines
-WARNING: This is an experimental feature.
+ WARNING: This is an experimental feature. Details are subject to change.
-change#4081
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>,
-Tuomas Lukka <lukka@iki.fi>)]
+Subroutines can now return modifiable lvalues.
+See L<perlsub/"Lvalue subroutines">.
=head2 "our" declarations
to check if you're running a particular version of Perl:
# this will parse in older versions of Perl also
- if ($^V and $^V gt v5.5.640) {
+ if ($^V and $^V gt v5.6.0) {
# new features supported
}
=head2 Weak references
-WARNING: This is an experimental feature.
+ WARNING: This is an experimental feature. Details are subject to change.
In previous versions of Perl, you couldn't cache objects so as
to allow them to be deleted if the last reference from outside
To use this feature, you need the WeakRef package from CPAN, which
contains additional documentation.
-change#3385, also need perlguts documentation
-[TODO - Tuomas Lukka <lukka@iki.fi>]
-
=head2 File globbing implemented internally
-WARNING: This is currently an experimental feature. Interfaces and
-implementation are likely to change.
+ WARNING: This is currently an experimental feature. Interfaces and
+ implementation are likely to change.
Perl now uses the File::Glob implementation of the glob() operator
automatically. This avoids using an external csh process and the
# $f implicitly closed here
}
-[TODO - this idiom needs more pod penetration]
+=head2 open() with more than two arguments
+
+If open() is passed three arguments instead of two, the second arguments
+is used as the mode and the third argument is taken to be the file name.
+This is primarily useful for protecting against unintended magic behavior
+of the traditional two-argument form. See L<perlfunc/open>.
=head2 64-bit support
- NOTE: The Configure flags -Duselonglong and -Duse64bits
- have been deprecated. Use -Duse64bitint instead.
+ NOTE: The Configure flags -Duselonglong and -Duse64bits have been
+ deprecated. Use -Duse64bitint instead.
+
+Any platform that has 64-bit integers either
-Any platform that has 64-bit integers either (a) natively as longs or
-ints (b) via special compiler flags (c) using long long are able to
-use "quads" (64-integers) as follows:
+ (1) natively as longs or ints
+ (2) via special compiler flags
+ (3) using long long or int64_t
+
+are able to use "quads" (64-bit integers) as follows:
=over 4
=item *
in bit arithmetics: & | ^ ~ << >> (NOTE: these used to be forced
-to be 32 bits wide.)
+to be 32 bits wide but now operate on the full native width.)
=item *
There are actually two modes of 64-bitness: the first one is achieved
using Configure -Duse64bitint and the second one using Configure
-Duse64bitall. The difference is that the first one is minimal and
-the second one maximal. The first one does only as much as is
-required to get 64-bit integers into Perl (this may mean, for example,
-using "long longs") while your memory may still be limited to 2
-gigabytes (because your pointers most likely are 32-bit); the second
-one goes all the way by attempting to switch also longs (and pointers)
-being 64-bit. This may create an even more binary incompatible Perl
-than -Duse64bitint: the resulting executable may not run at all in a
-CPU-bit box, or you may have to reboot/reconfigure/rebuild your
-operating system to be 64-bit aware.
+the second one maximal.
+
+The C<use64bitint> does only as much as is required to get 64-bit
+integers into Perl (this may mean, for example, using "long longs")
+while your memory may still be limited to 2 gigabytes (because your
+pointers could still be 32-bit). Note that the name C<64bitint> does
+not imply that your C compiler will be using 64-bit C<int>s (it might,
+but it doesn't have to): the C<use64bitint> means that you will be
+able to have 64 bits wide scalar values.
+
+The C<use64bitall> goes all the way by attempting to switch also
+integers (if it can), longs (and pointers) to being 64-bit. This may
+create an even more binary incompatible Perl than -Duse64bitint: the
+resulting executable may not run at all in a 32-bit box, or you may
+have to reboot/reconfigure/rebuild your operating system to be 64-bit
+aware.
Natively 64-bit systems like Alpha and Cray need neither -Duse64bitint
nor -Duse64bitall.
Last but not least: note that due to Perl's habit of always using
-floating point numbers the quads are still not true integers.
+floating point numbers, the quads are still not true integers.
When quads overflow their limits (0...18_446_744_073_709_551_615 unsigned,
-9_223_372_036_854_775_808...9_223_372_036_854_775_807 signed), they
are silently promoted to floating point numbers, after which they will
-start losing precision (their lower digits).
+start losing precision (in their lower digits).
=head2 Large file support
If you have filesystems that support "large files" (files larger than
2 gigabytes), you may now also be able to create and access them from
-Perl. You have to use Configure -Duselargefiles. Turning on the
-large file support turns on also the 64-bit support on many platforms.
-Beware that unless your filesystem also supports "sparse files" seeking
-to umpteen petabytes may be unadvisable.
+Perl. NOTE: the default action is to use the large file support, if
+available on the platform.
+
+If the large file support is on, and you have a Fcntl constant
+O_LARGEFILE, the O_LARGEFILE is automatically added to the flags
+of sysopen().
+
+Beware: unless your filesystem also supports "sparse files" seeking to
+umpteen petabytes may be unadvisable.
Note that in addition to requiring a proper file system to do large
files you may also need to adjust your per-process (or your
=head2 Enhanced support for sort() subroutines
-Perl subroutines with a prototype of C<($$)> and XSUBs in general can
+Perl subroutines with a prototype of C<($$)>, and XSUBs in general, can
now be used as sort subroutines. In either case, the two elements to
be compared are passed as normal parameters in @_. See L<perlfunc/sort>.
F<AutoSplit.pm> and F<SelfLoader.pm> have been updated to keep the attributes
with the stubs they provide. See L<attributes>.
-=head2 Regular expression improvements
-
-change#2827,2373,2372,2365,1813,1800,4112,4158,4215,4301
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
-
-=head2 Overloading improvements
-
-change#2150
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
-
-=head2 open() with more than two arguments
-
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
-
=head2 Support for interpolating named characters
-change#4052
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
-
-=head2 Experimental support for user-hooks in @INC
-
-[TODO - Ken Fox <kfox@ford.com>]
+The new C<\N> escape interpolates named characters within strings.
+For example, C<"Hi! \N{WHITE SMILING FACE}"> evaluates to a string
+with a unicode smiley face at the end.
=head2 C<require> and C<do> may be overridden
=head2 New variable $^V contains Perl version as a string
C<$^V> contains the Perl version number as a string composed of
-characters whose ordinals match the version numbers, e.g., v5.6.0.
+characters whose ordinals match the version numbers, i.e. v5.6.0.
This may be used in string comparisons.
See C<Support for strings represented as a vector of ordinals> for an
=head2 C<eval '...'> improvements
Line numbers (as reflected by caller() and most diagnostics) within
-C<eval '...'> were often incorrect when here documents were involved.
+C<eval '...'> were often incorrect where here documents were involved.
This has been corrected.
Lexical lookups for variables appearing in C<eval '...'> within
compilation as true errors rather than as warnings. This fixes
cases where error messages leaked through in the form of warnings
when code was compiled at run time using C<eval STRING>, and
-also allows such errors to be reliably trapped using __DIE__ hooks.
+also allows such errors to be reliably trapped using C<eval "...">.
=head2 Automatic flushing of output buffers
fork(), exec(), system(), qx//, and pipe open()s now flush buffers
-of all files opened for output when the operation
-was attempted. This mostly eliminates confusing
-buffering mishaps suffered by users unaware of how Perl internally
-handles I/O.
+of all files opened for output when the operation was attempted. This
+mostly eliminates confusing buffering mishaps suffered by users unaware
+of how Perl internally handles I/O.
+
+This is not supported on some platforms like Solaris where a suitably
+correct implementation of fflush(NULL) isn't available.
=head2 Better diagnostics on meaningless filehandle operations
=head2 C<(\$)> prototype and C<$foo{a}>
-An scalar reference prototype now correctly allows a hash or
+A scalar reference prototype now correctly allows a hash or
array element in that slot.
=head2 Pseudo-hashes work better
Numbers formatted according to the local numeric locale
(such as using a decimal comma instead of a decimal dot) caused
"isn't numeric" warnings, even while the operations accessing
-those numbers produced correct results. The warnings are gone.
+those numbers produced correct results. These warnings have been
+discontinued.
=head2 Memory leaks
later method lookups from progressing into base packages.
This has been corrected.
-=head2 Consistent numeric conversions
-
-change#3378,3318
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
-
=head2 Taint failures under C<-U>
When running in unsafe mode, taint violations could sometimes
used to truncate the message in prior versions.
$foo::a and $foo::b are now exempt from "possible typo" warnings only
-if sort() is encountered in package foo.
+if sort() is encountered in package C<foo>.
Unrecognized alphabetic escapes encountered when parsing quote
constructs now generate a warning, since they may take on new
semantics in later versions of Perl.
+Many diagnostics now report the internal operation in which the warning
+was provoked, like so:
+
+ Use of uninitialized value in concatenation (.) at (eval 1) line 1.
+ Use of uninitialized value in print at (eval 1) line 1.
+
+Diagnostics that occur within eval may also report the file and line
+number where the eval is located, in addition to the eval sequence
+number and the line number within the evaluated text itself. For
+example:
+
+ Not enough arguments for scalar at (eval 4)[newlib/perl5db.pl:1411] line 2, at EOF
+
=head1 Performance enhancements
=head2 Simple sort() using { $a <=> $b } and the like are optimized
optimized to directly set the lexical variable on the LHS,
eliminating redundant copying overheads.
-=head2 Method lookups optimized
-
-[TODO - Chip Salzenberg <chip@perlsupport.com>]
-
-=head2 Faster mechanism to invoke XSUBs
-
-change#4044,4125
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
-
-=head2 Perl_malloc() improvements
-
-change#4237
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
-
=head2 Faster subroutine calls
Minor changes in how subroutine calls are handled internally
=item *
-Wrong exit code from backticks now fixed.
+Incorrect exit codes from backticks have been fixed.
=item *
-This port is still using its own builtin globbing.
+This port continues to use its own builtin globbing (not File::Glob).
=back
-=head2 OS/2
-
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
-
-=head2 OS/390 (OpenEdition MVS)
+=head2 OS390 (OpenEdition MVS)
Support for this EBCDIC platform has not been renewed in this release.
There are difficulties in reconciling Perl's standardization on UTF-8
=head2 VMS
Numerous revisions and extensions to configuration, build, testing, and
-installation process to accomodate core changes and VMS-specific options
+installation process to accomodate core changes and VMS-specific options.
Expand %ENV-handling code to allow runtime mapping to logical names,
-CLI symbols, and CRTL environ array
+CLI symbols, and CRTL environ array.
-Extension of subprocess invocation code to accept filespecs as command "verbs"
+Extension of subprocess invocation code to accept filespecs as command
+"verbs".
Add to Perl command line processing the ability to use default file types and
-to recognize Unix-style C<2E<gt>&1>.
+to recognize Unix-style C<2E<gt>&1>.
-Expansion of File::Spec::VMS routines, and integration into ExtUtils::MM_VMS
+Expansion of File::Spec::VMS routines, and integration into ExtUtils::MM_VMS.
-Extension of ExtUtils::MM_VMS to handle complex extensions more flexibly
+Extension of ExtUtils::MM_VMS to handle complex extensions more flexibly.
Barewords at start of Unix-syntax paths may be treated as text rather than
-only as logical names
+only as logical names.
-Optional secure translation of several logical names used internally by Perl
+Optional secure translation of several logical names used internally by Perl.
-Miscellaneous bugfixing and porting of new core code to VMS
+Miscellaneous bugfixing and porting of new core code to VMS.
Thanks are gladly extended to the many people who have contributed VMS
patches, testing, and ideas.
=head2 Win32
-Site library searches failed to look for ".../site/5.XXX/lib"
-if ".../site/5.XXXYY/lib" wasn't found. This has been corrected.
+Perl can now emulate fork() internally, using multiple interpreters running
+in different concurrent threads. This support must be enabled at build
+time. See L<perlfork> for detailed information.
-When given a pathname that consists only of a drivename, such
-as C<A:>, opendir() and stat() now use the current working
-directory for the drive rather than the drive root.
+When given a pathname that consists only of a drivename, such as C<A:>,
+opendir() and stat() now use the current working directory for the drive
+rather than the drive root.
-The builtin XSUB functions in the Win32:: namespace are
-documented. See L<Win32>.
+The builtin XSUB functions in the Win32:: namespace are documented. See
+L<Win32>.
$^X now contains the full path name of the running executable.
The C<Shell> module is supported.
-Rudimentary support for building under command.com in Windows 95
+Better support for building Perl under command.com in Windows 95
has been added.
Scripts are read in binary mode by default to allow ByteLoader (and
which supports glob syntax of the C shell. This increases the flexibility
of the glob() operator, but there may be compatibility issues for
programs that relied on the older globbing syntax. If you want to
-preserve compatibility with the older syntax, you might want to put
-a C<use File::DosGlob;> in your program. For details and compatibility
-information, see L<File::Glob>.
-
-[TODO - GSAR]
+preserve compatibility with the older syntax, you might want to run
+perl with C<-MFile::DosGlob>. For details and compatibility information,
+see L<File::Glob>.
=head1 New tests
=item B
-The Perl Compiler suite has been extensively reworked for this
-release.
+ WARNING: The Compiler suite remains highly experimental. The
+ generated code may not be correct, even it manages to execute
+ without errors.
-[TODO - Vishal Bhatia <vishal@gol.com>,
-Nick Ing-Simmons <nick@ni-s.u-net.com>]
+The Perl Compiler suite has been extensively reworked for this
+release. More of the standard Perl testsuite passes when run
+under the Compiler, but there is still a significant way to
+go to achieve production quality compiled executables.
=item ByteLoader
=item charnames
-change#4052
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
+This pragma implements the C<\N> string escape. See L<charnames>.
=item Data::Dumper
A C<Maxdepth> setting can be specified to avoid venturing
too deeply into deep data structures. See L<Data::Dumper>.
+The XSUB implementation of Dump() is now automatically called if the
+C<Useqq> setting is not in use.
+
Dumping C<qr//> objects works correctly.
=item DB
accuracy.
You can now run tests for I<n> seconds instead of guessing the right
-number of tests to run: e.g. timethese(-5, ...) will run each
+number of tests to run: e.g., timethese(-5, ...) will run each
code for at least 5 CPU seconds. Zero as the "number of repetitions"
means "for at least 3 CPU seconds". The output format has also
changed. For example:
Env now supports accessing environment variables like PATH as array
variables.
-=item ExtUtils::MakeMaker
-
-change#4135, also needs docs in module pod
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
-
=item Fcntl
More Fcntl constants added: F_SETLK64, F_SETLKW64, O_LARGEFILE for
-large file (more than 4GB) access Note that the O_LARGEFILE is
-automatically/transparently added to sysopen() flags if large file
-support has been configured), Free/Net/OpenBSD locking behaviour flags
-F_FLOCK, F_POSIX, Linux F_SHLCK, and O_ACCMODE: the combined mask of
-O_RDONLY, O_WRONLY, and O_RDWR. The seek()/sysseek() constants
-SEEK_SET, SEEK_CUR, and SEEK_END are available via the C<:seek> tag.
-The chmod()/stat() S_IF* constants and S_IS* functions are available
-via the C<:mode> tag.
-
+large file (more than 4GB) access (NOTE: the O_LARGEFILE is
+automatically added to sysopen() flags if large file support has been
+configured, as is the default), Free/Net/OpenBSD locking behaviour
+flags F_FLOCK, F_POSIX, Linux F_SHLCK, and O_ACCMODE: the combined
+mask of O_RDONLY, O_WRONLY, and O_RDWR. The seek()/sysseek()
+constants SEEK_SET, SEEK_CUR, and SEEK_END are available via the
+C<:seek> tag. The chmod()/stat() S_IF* constants and S_IS* functions
+are available via the C<:mode> tag.
=item File::Compare
The accessor methods Re, Im, arg, abs, rho, and theta can now also
act as mutators (accessor $z->Re(), mutator $z->Re(3)).
+The class method C<display_format> and the corresponding object method
+C<display_format>, in addition to accepting just one argument, now can
+also accept a parameter hash. Recognized keys of a parameter hash are
+C<"style">, which corresponds to the old one parameter case, and two
+new parameters: C<"format">, which is a printf()-style format string
+(defaults usually to C<"%.15g">, you can revert to the default by
+setting the format string to C<undef>) used for both parts of a
+complex number, and C<"polar_pretty_print"> (defaults to true),
+which controls whether an attempt is made to try to recognize small
+multiples and rationals of pi (2pi, pi/2) at the argument (angle) of a
+polar complex number.
+
+The potentially disruptive change is that in list context both methods
+now I<return the parameter hash>, instead of only the value of the
+C<"style"> parameter.
+
=item Math::Trig
A little bit of radial trigonometry (cylindrical and spherical),
for advanced users of Pod::Parser that need more about a command besides
its name and text.
-As of release 5.6 of Perl, Pod::Parser is now the officially sanctioned
+As of release 5.6.0 of Perl, Pod::Parser is now the officially sanctioned
"base parser code" recommended for use by all pod2xxx translators.
Pod::Text (pod2text) and Pod::Man (pod2man) have already been converted
to use Pod::Parser and efforts to convert Pod::HTML (pod2html) are already
C<File::Spec::Unix>). L<Pod::ParseUtils|Pod::ParseUtils> contains
B<Pod::List> (useful for storing pod list information), B<Pod::Hyperlink>
(for parsing the contents of C<LE<lt>E<gt>> sequences) and B<Pod::Cache>
-(for caching information about pod files, e.g. link nodes).
+(for caching information about pod files, e.g., link nodes).
=item Pod::Select, podselect
=item Pod::Text and Pod::Man
-[TODO - Russ Allbery <rra@stanford.edu>]
+Pod::Text has been rewritten to use Pod::Parser. While pod2text() is
+still available for backwards compatibility, the module now has a new
+preferred interface. See L<Pod::Text> for the details. The new Pod::Text
+module is easily subclassed for tweaks to the output, and two such
+subclasses (Pod::Text::Termcap for man-page-style bold and underlining
+using termcap information, and Pod::Text::Color for markup with ANSI color
+sequences) are now standard.
+
+pod2man has been turned into a module, Pod::Man, which also uses
+Pod::Parser. In the process, several outstanding bugs related to quotes
+in section headers, quoting of code escapes, and nested lists have been
+fixed. pod2man is now a wrapper script around this module.
=item SDBM_File
Sys::Hostname now uses XSUBs to call the C library's gethostname() or
uname() if they exist.
+=item Term::ANSIColor
+
+Term::ANSIColor is a very simple module to provide easy and readable
+access to the ANSI color and highlighting escape sequences, supported by
+most ANSI terminal emulators. It is now included standard.
+
=item Time::Local
The timelocal() and timegm() functions used to silently return bogus
backward-compatibility. It's been replaced by the C<sub : attributes>
syntax. See L<perlsub/"Subroutine Attributes"> and L<attributes>.
-C<use utf8> to enable UTF-8 and Unicode support.
-
Lexical warnings pragma, C<use warnings;>, to control optional warnings.
See L<perllexwarn>.
=head1 Utility Changes
-=head2 h2ph
-
-[TODO - Kurt Starsinic <kstar@chapin.edu>]
-
=head2 perlcc
C<perlcc> now supports the C and Bytecode backends. By default,
Support for non-Unix platforms has been improved.
-=head2 h2xs
+=head2 perldoc
+
+C<perldoc> has been reworked to avoid possible security holes.
+It will not by default let itself be run as the superuser, but you
+may still use the B<-U> switch to try to make it drop privileges
+first.
-change#4232
-[TODO - Ilya Zakharevich <ilya@math.ohio-state.edu>]
+=head2 The Perl Debugger
+
+Many bug fixes and enhancements were added to F<perl5db.pl>, the
+Perl debugger. The help documentation was rearranged. New commands
+include C<< < ? >>, C<< > ? >>, and C<< { ? >> to list out current
+actions, C<man I<docpage>> to run your doc viewer on some perl
+docset, and support for quoted options. The help information was
+rearranged, and should be viewable once again if you're using B<less>
+as your pager. A serious security hole was plugged--you should
+immediately remove all older versions of the Perl debugger as
+installed in previous releases, all the way back to perl3, from
+your system to avoid being bitten by this.
=head1 Documentation Changes
An introduction to using the Perl Compiler suite.
+=item perldebug.pod
+
+All material unrelated to running the Perl debugger, plus all
+low-level guts-like details that risked crushing the casual user
+of the debugger, have been relocated from the old manpage to the
+next entry below.
+
+=item perldebguts.pod
+
+This new manpage contains excessively low-level material not related
+to the Perl debugger, but slightly related to debugging Perl itself.
+It also contains some arcane internal details of how the debugging
+process works that may only be of interest to developers of Perl
+debuggers.
+
=item perlfilter.pod
An introduction to writing Perl source filters.
will interfere with proper determination of exit status of child
processes, Perl has reset the signal to its default value.
This situation typically indicates that the parent program under
-which Perl may be running (e.g. cron) is being very careless.
+which Perl may be running (e.g., cron) is being very careless.
=item Can't modify non-lvalue subroutine call
(F) Compile-time-substitutions (such as overloaded constants and
character names) were not correctly set up.
+=item CORE::%s is not a keyword
+
+(F) The CORE:: namespace is reserved for Perl keywords.
+
=item defined(@array) is deprecated
(D) defined() is not usually useful on arrays because it checks for an
(W) You are concatenating the number 19 with another number, which
could be a potential Year 2000 problem.
+=item pragma "attrs" is deprecated, use "sub NAME : ATTRS" instead
+
+(W) You have written somehing like this:
+
+ sub doit
+ {
+ use attrs qw(locked);
+ }
+
+You should use the new declaration syntax instead.
+
+ sub doit : locked
+ {
+ ...
+
+The C<use attrs> pragma is now obsolete, and is only provided for
+backward-compatibility. See L<perlsub/"Subroutine Attributes">.
+
+
=item Premature end of script headers
See Server error.
=back
+=head1 Known Problems
+
+=head2 Thread tests failing
+
+The subtests 19 and 20 of the lib/thread test are known to fail in
+many platforms.
+
+=head2 EBCDIC platforms not supported
+
+In earlier releases of Perl the EBCDIC environments like OS390 (also
+known as Open Edition MVS) and VM-ESA were supported. Due to the
+changes required by the UTF-8 (Unicode) support in Perl 5.6 the EBCDIC
+platforms are not supported in Perl 5.6.0.
+
+=head2 NEXTSTEP 3.3 POSIX test failure
+
+In NEXTSTEP 3.3p2 the implementation of the strftime(3) in the
+operating system libraries is buggy: the %j format numbers the days of
+a month starting from zero, which, while being logical to programmers,
+will cause the subtests 19 to 27 of the lib/posix test may fail.
+
+=head2 UNICOS/mk CC failures during Configure run
+
+In UNICOS/mk the following errors may appear during the Configure run:
+
+ Guessing which symbols your C compiler and preprocessor define...
+ CC-20 cc: ERROR File = try.c, Line = 3
+ ...
+ bad switch yylook 79bad switch yylook 79bad switch yylook 79bad switch yylook 79#ifdef A29K
+ ...
+ 4 errors detected in the compilation of "try.c".
+
+The culprit is the broken awk of UNICOS/mk. The effect is fortunately
+rather mild: Perl itself is not adversely affected by the error, only
+the h2ph utility coming with Perl, and that is rather rarely needed
+these days.
+
+=head2 Many features still experimental
+
+As discussed above, many features are still experimental, to a greater
+or lesser degree. Interfaces and implementation are subject to
+change, in extreme cases even subject to removal in some future
+release of Perl. These features include the following:
+
+=over 4
+
+=item Threads
+
+=item Unicode
+
+=item Lvalue subroutines
+
+=item Weak references
+
+=item File globbing now implemented internally
+
+=item The Compiler suite
+
+=item the DB module
+
+=item the regular expression constructs C<(?{ code })> and C<(??{ code })>
+
+=back
+
=head1 BUGS
If you find what you think is a bug, you might check the
Home Page.
If you believe you have an unreported bug, please run the B<perlbug>
-program included with your release. Make sure to trim your bug down
+program included with your release. Be sure to trim your bug down
to a tiny but sufficient test case. Your bug report, along with the
output of C<perl -V>, will be sent off to perlbug@perl.com to be
analysed by the Perl porting team.